Vermont State Police say they received a call concerning the death of an inmate at Southern State Correctional Facility in Springfield.

The inmate, identified as Sylvester Labartino, of Hubbardton, was awaiting trial for the February fatal shootings of Christopher and Shane Plummer. The Plummers were a father and son team of electricians who had been working at Labartino's rented home.

Police say Labartino, who has been incarcerated since his arrest, had been recently diagnosed with a serious medical condition, and had a history of debilitating medical disorders. He was admitted to the prison’s infirmary last week as his condition worsened. An autopsy will be conducted. Police did not disclose what the medical conditions were.

Police believe his death to be due to natural causes.

Police say although there are no signs of foul play, the case is ongoing pending additional investigation and results of the autopsy.